Telephone-transmitter.



H. G. EGERTON.

TELEPHONE TRANSMITTER. APPLICATION FILED 0GT.5,1912. RENEWED MAY24.1913.

1,073,667. Patented Sept. 23, 1913.

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(9%, we. by y 9- -4) therctht'oug EGERTON, 0F PASSAIC, NEW JERSEY,ASSIGNOR TO \VESTERN ETJJC'IPRIG anus? c.

a a oinniei-ii.

GOMEANY, OF NEW YORK, N. Y A CORPORATION OF ILLINOIS.

TELEPHONE-TRANSMITTER.

Specification of Letters Patent.

llifili tltlmll flied 066316? 5, 191%, Serial 1V0. 724,056. Renewed May24, 1913. Serial No. 769,765.

To all whom it may concern Be it known that I, IIENR'Y C. Eonn'nim. acitizen of the United States, residing at Passaic, in the county ofPassaic and State of New Jersey, have invented a certain new and usefulimprovement in Telephoneiransmitters, of which the following is a fullclear, concise, and exact description.

This invention relates to telephone transmitting apparatus and has forits object to provide a transmitter of few and simple parts which willbe efficient in its operation and easily assembled.

In accordance with one of the features of this invention, the movableelectrode is mounted directly upon the transmitter diaphragm and in theassembly of the device is inciosed by means of a containing chamberformed in a metal section of the structure.-

Another feature of this invention relates to the means provided forsealing the chamber without appreciably reducing the heat radiation, andconsists in the provision of a thin washer of comparatively resilientinsulating material secured directly to the dia phragm against which theedge of the con taining cup bears. For this purpose a thin washer ofhard felt is found to be satisfac" tory'inasmuch as it permitssufficient movement of the diaphragm and will notpack or shrink to suchan extent as to permit the comminnted material to escape from thechamber.

In the drawings in which this invention is illustrated in connectionwith a push and pull type of transmitter comprising two iixcd and twomovable electrodes, Figure l i is a sectional View of a transmitterembodying this invention; and Fig. 2 is a detail view of the principalparts of the trans niitte'i".

As shown in the drawings, 5 designates the usual transmitter mouthpiecehaving screw-threaded engagement with a metal plate 6 which is providedat its center with a chamber or recessed portion 7 and a web portion 8havin a )iurality of openings h leaning into the chamber 7. Formed uponthis weh portion 8 is a lug 10', the outer end of which is of conicalform and projects into the mouthpiece 5 to deflect the voice rcurrentthronghthc openings 9" The inner end ol the lug 10 is recessed to form achamber ii. Mounted in one end of this chamber is a screw-tilrca'dcdstud 13 to which secured an electrode l-l. Secured to the back face ofthe meta] plate (3 a second metal plate 18 having a recessed or chamberportion 1.) at its ccntcr. a wch portion 20 and a lug 21 with an opcningthercthrongh in one end of which is mounted a metal stud 23 carrying anelectrode 24. The portion of the web surrounding the log 21 is providedwith (nicnings ZS- 21) for the passage of air from the chamber orrecessed portion it). Mounted bctwocn the plates (3 and 18 is avibrating diaphragm 130 which is insulated from said plate by m ans of arubber gasket or ring 31. The plates (3 and 18 are secured together bymeans of screws Bil--32 extending through the plate 18 and engaging theplate o. lhcsc screws pass through insulating bushing;- ill :l-l. in theplate 18 and an insulating uashcr 353 is interposed hetwccn these plalcsnear their outer margins. A metal spacing ring 236 is also interposedlit-tween these plates to maintain their relation with each other andwith the diaphragm 30.

Mounted upon opposite sidcs oi the din phragiu 30 on thc central portiontlicrcol. are two electrodes 10 and H. These clcctrodes are secured tostuds l2 and -l -l one of which has an interior scrcw-lhrcadcd por--tion 17 passing through the diaphragm 30 to receive an extcriorlyscrcw-thrcadcd portion 48 upon the other of said studs. Spacing washers41) and 50 are iulcrposcd between the back faces of the studs carryingthe clcctrodes and serve also as an electrical coin nection between saidstuds and said dia pln'agm. ".lhe elcctrodcs 35 and ill; extend into thechamber portions of the metal studs 1d and 31 respectively. Fiecnred tothe diaphragni 30 one on each side thereof are felt rings 5L and 52again t which the inner ends of the studs 10 and P! bear. These 't'clt,washers extend beyond the margins of the electrodes 10 and ll, and sealthe openings 01 the chambers it and which are par tially tilled withcomminutcd material 55.

As shown, stud 23 carrying the electrode 3-1; is mounted in a plate 59which is adapted to be secured to the plate 18 by means f till terial,then the diaphragm bearing movable electrodes and the felt Washers willbe placed-in position and the metal plates 6 and 18 secured together.Then by supplying the comminuted material to the chamber 22 and securingplate 59 thereto with the electrode in place the instrument, will beready for operation.

Secured at one end to the diaphragm 30 and-at its other end to the metalplate 18 is a bowed metal spring 67 constituting a damping andcircuit-connecting spring.

The structure as above described may be mounted in an ordinarytransmitter bell 65 which may be secured to a desk stand or well set inthe well known manner.

The advantages of the structure above described are the elimination ofmica or auxiliary diaphragms for closing the granule phra containingchambers. The radiation qualities of thedevice are not affected inasmuchas the electrodes and the contained comminuted material are so relatedto the'metal walls of the containing cups that the heat generated insaid electrodes and comminuted material will find a ready path throughsaid walls unaffected by the felt washers. this structure by the use ofthe hard felt is that after the instrument has been used a short timethe felt mats down slightly where it touches the edge of the buttonchamber but not sufficient to permit the escape of.the comminutedmaterial from the chamber. Thiswill improve the transmission due to thegreater freedom with which the diaphragm vibrates. While .this inventionis shown and described in connection with a push and pull type oftransmitter-in which there are. employed two movable and two iixedelectrodes, it will be readily apparent to those skilled in the art thatthe invention is not limited to this form of transmitter as it is alsoapplicable to asinglebutton type of transmitter for use with theordinary telephone currents. Such a structure would result from. theomission of the front electrode chamber and associated parts and all ofthe advantages of .the invention would be embodied in such modifiedstructure.

I claim 1. In a telephone transmitter, a diaphragm, frame plates betweenwhich said diaphragm is supported, a granule contain ing cup carried byeach of said frame plates, electrodes supported by said diaphragm insaidcups, and means carried by said diam for sealing said cups.

n. a telephone transmitter, a diaphra in, frame plates between whichsaid diap ragm is supported, a granule c0ntain-' Another advantageobtained, in

noraeer ing cup formed integrally virith each of said frame plates,electrodes supportedby said.

diaphragm in said cups and means carried by said diaphragm for sealingsaid cups.

3. In a. telephone transmitter, a diaphragm, frame plates between whichsaid diaphragm is supported, a granule contain in on carried h each ofsaid lates elec-- trodes mounted upon opposite sidesof saio diaphragmand located in said cups, 1 resilient insulating washers mounted upeopposite sides of said diaphragm against which the adjacent ends of saidcups bear.

4. In a telephone transmitter, a diaphragm, frame plates between whichsaid diaphragm is supported, a granule containing cup fdrmed integrallywith each of said plates, electrodes mounted upon opposite sides of saiddiaphragm and hard felt washers secured to the opposite faces of saiddiaphragm against which the adjacent ends of said cups bear.

5. In a telephone transmitter, a dia phragm, frame plates between whichsaid diaphragm is supported, movable electrodes mounted upon oppositesides of said dia phragm, granule containing chambers formed 1 phragm, alug formed integrally with said front plate, said lug having aconicalprojection on one end and. being provided at its opposite end with achambered portion surrounding one of said movable electrodes, astationary electrode mounted in said chamher, a lug formed upon saidback plate and having an opening therethrough, one end of whichsurrounds a movable electrode carried by said diaphragm, a stationaryelectrodefor closing the rear end of said opening and a detachable platecarrying said last named stationary electrode. said detachable plate beg setured to said back mounting plate.

.In a telephone transmitter, a dia phragm, frame plates for supportingsaid diaphragm, a granule containing-cup car" ried by one of said frameplates, an electrode supported by said diaphragm in said cup,

and means carried by said diaphragm tor sealing said cup.

8.111 a telephone transmitter, a diaphragm, frame plates between whichsaid diaphragm is supported, a granule contain- 'ing-cup formedintegrally with one of said frame plates, an electrode supported by saiddiaphragm in said cup, andmeans carried by said iaphragm for sealing'said cup,

9. In a telephone transm tter,- a diaphragm, frame plates between whichsaid dizqphi-ngn'i is supported, a granule containing-(Hp carried by oneof said plates, an electrode mounted upon said diaphragm and iUC'fllCliin said cup, and a resilient insulating washer mounted upon saiddiaphragm ngninst \vhivh H10 :u ljnucnt end of the cup limits.

In witness whereof, I hersunto subscriim in v name this third day of()L'iIOiJLZI A. .11,

HENRY C. EGER'lON. \Vii IIQSSCS GEO. TIIJJS PIERCE, Jusm'n A. Gm'mLY

